Medical physics is the application of physics to medicine. It generally concerns physics as applied to medical imaging and radiotherapy, although a medical physicist may also work in many other areas of healthcare. A medical physics department may be based in either a hospital or a university and its work is likely to include research, technical development, and clinical healthcare.
Of the large body of medical physicists in academia and clinics, roughly 85% practice or specialize in various forms of therapy, 10% in diagnostic imaging, and 5% in nuclear medicine.
Areas of specialty in medical physics however are widely varied in scope and breadth.
Para-sagittal MRI of the head in a patient with benign familial macrocephaly
Areas of specialty
Medical imaging
• Diagnostic radiology, including x-rays, fluoroscopy, mammography, Dual energy X-ray absorptiometry, angiography and Computed tomography
• Ultrasound, including intravascular ultrasound
• Non-ionizing radiation (Lasers, Ultraviolet etc.)
• Nuclear medicine, including SPECT and positron emission tomography (PET)
• Magnetic resonance imaging (MRI), including functional magnetic resonance imaging (fMRI) and other methods for functional neuroimaging of the brain.
o For example, nuclear magnetic resonance (often referred to as magnetic resonance imaging to avoid the common concerns about radiation), uses the phenomenon of nuclear resonance to image the human body.
• Magnetoencephalography
• Electrical impedance tomography
• Diffuse optical imaging
• Optical coherence tomography
Treatment of disease
• Defibrillation
• High intensity focussed ultrasound, including lithotripsy
• Interventional radiology
• Non-ionising radiation Lasers, Ultraviolet etc. including photodynamic therapy and Lasik
• Nuclear medicine, including unsealed source radiotherapy
• Photomedicine, the use of light to treat and diagnose disease
• Radiotherapy
o TomoTherapy
o Cyberknife
o Gamma knife
o Proton therapy
o Brachytherapy
o Boron Neutron Capture Therapy
• Sealed source radiotherapy
• Terahertz radiation
Physiological measurement techniques
ECG trace
Used to monitor and measure various physiological parameters. Many physiological measurement techniques are non-invasive and can be used in conjunction with, or as an alternative to, other invasive methods.
• Electrocardiography
• Electromyography
• Electroencephalography
• Electronystagmography
• Endoscopy
• Medical ultrasonography
• Non-ionising radiation (Lasers, Ultraviolet etc.)
• Near infrared spectroscopy
• Pulse oximetry
• Blood gas monitor
• Blood pressure measurement
Radiation protection
• Background radiation
• Radiation protection
• Dosimetry
• Health Physics
• Radiological Protection of Patients
Medical computing and mathematics
CT image reconstruction
• Medical informatics
• Telemedicine
• Picture archiving and communication systems (PACS)
• DICOM
• Tomographic reconstruction, an ill-posed inverse problem
• Advanced Digital Imaging Solutions Laboratory[ADISL][2]
Education and training
The primary clinical responsibility of the Qualified Medical Physicist is to “assure the safe and effective delivery of radiation to achieve a diagnostic or therapeutic result as prescribed in patient care (Medical Physics Scope of Practice)”.[3] Various training programs exist to accommodate the demand for specialization in this field.
In North America
In North America, medical physics training is offered at a master’s, doctorate, post-doctorate and/or residency levels. Several large and established universities offer these degrees in Canada and the United States. Some programs such as the University of Texas Health Science Center Department of Radiology offer dual medical residency and Ph.D. degrees in medical physics.[4] As of 2008, twelve universities in the United States, and five universities in Canada have graduate programs in Medical Physics that are accredited by The Commission on Accreditation of Medical Physics Education Programs (CAMPEP). Pursuant to a strong recommendation from the American Association of Physicists in Medicine[5], the American Board of Radiology has specified that graduation from a CAMPEP-accredited training program be considered a requirement to sit for the ABR certification exams beginning in 2012.[6][7][8] Graduation from a CAMPEP-accredited residency will be required beginning in 2014. As of 2008, the number of medical physics graduate programs that are not accredited significantly outnumber the CAMPEP accredited programs in North America [9][10]. The American Association of Physicists in Medicine has proposed mechanisms for quickly establishing the additional training slots.[11]
In the United States, the Consumer Assurance of Radiologic Excellence Act (H.R. 1426) also called the CARE Bill (under consideration by the U.S. congress in 2007) mandates that states which receive federal Medicaid funds must establish minimum qualifications for individuals to practice medical physics. ABR certification will likely play an increasingly important role in establishing qualification to practice.
In the United Kingdom
The person concerned must first gain a first or upper second-class honours degree in a physical or engineering science subject before they can start the Grade A medical physics training within the NHS.
Trainees can complete Grade A training in fifteen months provided they hold an MSc from an IPEM accredited center in the United Kingdom or the Republic of Ireland (National University of Ireland, Galway). For these candidates, the grade A training consists of pure clinical experience. Trainees applying for grade A trainee holding only a degree in a physical or engineering science subject must undertake a combined study and clinical training programme. This programme consists of two years of clinical placement, during which the trainee will study for an MSc in Medical Physics which is approved by the Institute of Physics and Engineering in Medicine (IPEM). The MSc will be either at Swansea, Sheffield, Surrey, Birmingham, Leeds, Manchester, Aberdeen, King’s or Queen Mary’s. Open University also offers a Master of Science in Medical Physics, but the prospective student should first check that this degree will satisfy the accreditation requirements or that it is accepted before embarking on it. Successful completion of the Grade A training programme leads to an IPEM Diploma. The trainee can then apply for a Grade B position, which will consists of the IPEM’s Programme of Advanced Training (PAT) which takes a further two years and leads to Corporate Membership of the IPEM. At this stage the physicist is eligible for Senior Grade B positions.
Legislative and advisory bodies
• ICRU: International Commission on Radiation Units and Measurements
• ICRP: International Commission on Radiological Protection
• NCRP: National Council on Radiation Protection & Measurements
• NRC: Nuclear Regulatory Commission
• FDA: Food and Drug Administration
• IAEA: International Atomic Energy Agency
